Question

A transmission line is made of a core of copper surrounded by a concentric circular sheath of steel to give it strength. The copper core is 1.0 cm in diameter and the tightly fitting sheath has an outer diameter of 2.0 cm. What is the resistance of 1.0 km of this transmission line? What is the ratio of the current carried by the core to that carried by the sheath? What is the ratio of the power lost in the core to that lost in the sheath?